code: def test_load_from_file():
      gis = ImageSignature()
      sig = gis.generate_signature("test.jpg")
      assert type(sig) is ndarray
      assert sig.shape == (648,)
  
file_path: image-match/tests/test_goldberg.py
imports: import pytest
  from numpy import ndarray, array_equal
  from image_match.goldberg import ImageSignature, CorruptImageError
label_desc: Use image node_id 2 for calling a global function with example usage: test_load_from_file() without return types